So-called smelt salts based on phosphates and citrates have conventionally been used for the production of soft or process cheese. Such salts cause the known sol/gel transformation of the paracaseinate contained in the raw cheese with a stable emulsion of lactalbumin, milk fat and water being formed under the application of heat and mechanical agitation.
Such processes are supported, among other things, by transformation of the calcium paracaseinate into the soluble sodium salt through ion exchange with the smelt phosphates as used. In parallel thereto, a hydration takes place in which water is firmly integrated by electrostatic forces into the molecular bond of the peptide chain of the casein.
The extent to which calcium can be masked and, hence, protein can be dispersed depends on the smelt salt effect. In this manner, by suitable use of the smelt phosphates, hydration and viscosity increase of the melt can be controlled. If the effect of the phosphates is excessive, the peptide chains may be split into too short-linked aggregates, which, practically, can be equated with the state of over-creaming. That state will invariably occur if the hydration capacity of the paracasein is depleted and the colloidal "soft cheese" system become unstable. The soft cheese will then harden under the outflow of water to form a crumbly and cracky material.
Such emulsion disturbances, among other things, can also be caused by the presence of Ca++ ions that are not complexbonded as a result of unsuitable smelt salt combinations. Occasionally, raw cheeses also contain increased Ca contents which during smelting result in faulty products.
For this reason, hitherto, it has not been possible to use calcium-bearing salts in the production of soft cheese. From the point of view of the much-discussed Ca/P ratio in human food, for example, calcium phosphates would be a highly interesting product class. Even insoluble types such as dicalcium phosphate or commercially available tricalcium phosphate having a CaO/P.sub.2 O.sub.5 ratio of 3.15-3.40:1 are soluble to a certain extent and cause emulsion disturbances. Also, these calcium phosphates, in the weakly acid range, solubilize additional Ca++ ions. Process cheese normally is molten in a weakly acid pH range of between 5.5-6.0. However, that pH range is already sufficient to split off active Ca++ ions from the prior known and commercially available Ca-phosphates, resulting after a short storage time in a denaturation of the casein, combined with a hard and cracky consistency. Moreover, point-shaped, white metabolites are formed together with a "sandy" consistency of the soft cheese. In that state, the process cheese can be considered to be a faulty product which is unmarketable.